Compact vehicle tire lift/carrier winch mechanisms have been used in the past to store a spare tire beneath a vehicle such as an automobile, truck and the like.
U.S. Pat. No. 4,059,197 issued Nov. 22, 977, to Iida, U.S. Pat. No. 4,535,973 issued Aug. 20, 1985 to Dorr et al, U.S. Pat. No. 4,544,136 issued Oct. 1, 1985 to Denman et al and U.S. Pat. No. 4,625,947 issued Dec. 2, 1986, to Denman et al disclose compact winch mechanisms for tire lift/carriers wherein an eccentric gear arrangement is employed to provide a mechanical advantage in driving the sheave assembly of the winch in rotation to wind or unwind the cable connected to the spare tire carrier frame.
In these patented winch mechanisms, the sheave assembly typically includes a pair of sheave side plates maintained in spaced apart relation by suitable fasteners such as rivets and a sheave center plate having a peripheral edge forming a cable-wrapping track on which the cable is wrapped or unwrapped depending upon the direction of rotation of the sheave assembly. The spacing between the sheave side plates is selected to cause the cable to wind or wrap on itself as the sheave assembly is rotated. An annular driven gear is typically press fit in driving relation to one of the sheave side plates. Gear teeth on a reciprocable torque arm mesh with gear teeth on the annular driven gear to rotate the sheave assembly.
The winch cable typically is attached to the sheave assembly by affixing an enlarged cylindrical sheave member onto the cable end and forming side-by-side apertures in the sheave side plates and the sheave center plate to receive the enlarged sheave member affixed on the cable end. In particular, the enlarged sheave member is dimensioned to extend into apertures in the sheave side plates and to ride on rims of the side plates defining the apertures therein as the sheave assembly is rotated.
Copending U.S. patent application Ser. No. 170,281 of common assignee discloses a sheave assembly for a tire lift/carrier winch wherein the sheave center plate is molded, such as die cast, about an end of the winch cable to form a unitary sheave center plate and cable subassembly that simplifies manufacture and assembly of the tire lift/carrier winch.
Copending U.S. patent application Ser. No. 270,270 of common assignee describes a sheave assembly for a tire lift/carrier winch wherein the cable end fitting is rotatably mounted between the sheave side plates and includes an exterior, arcuate, cable-wrapping shoulder that is generally contiguous with the cable-wrapping track on the center sheave plate when the cable end fitting is in a "cable wrap/unwrap" position. When the sheave is rotated in the proper wrap direction, the cable is wrapped initially on the cable-wrapping shoulder and the cable-wrapping track and then onto itself.
In the manufacture of compact tire lift/carrier winches, it would be desirable to reduce the number and complexity of the components of the sheave assembly as well as the drive train. It would also be desirable to simplify the assembly of the tire lift/carrier winch. It would further be desirable to reduce the cost of the tire lift/carrier winch.